Search icon CANCEL
Subscription
0
Cart icon
Your Cart (0 item)
Close icon
You have no products in your basket yet
Arrow left icon
Explore Products
Best Sellers
New Releases
Books
Videos
Audiobooks
Learning Hub
Free Learning
Arrow right icon
Arrow up icon
GO TO TOP
Learning PySpark

You're reading from   Learning PySpark Build data-intensive applications locally and deploy at scale using the combined powers of Python and Spark 2.0

Arrow left icon
Product type Paperback
Published in Feb 2017
Publisher Packt
ISBN-13 9781786463708
Length 274 pages
Edition 1st Edition
Languages
Arrow right icon
Authors (2):
Arrow left icon
Denny Lee Denny Lee
Author Profile Icon Denny Lee
Denny Lee
Tomasz Drabas Tomasz Drabas
Author Profile Icon Tomasz Drabas
Tomasz Drabas
Arrow right icon
View More author details
Toc

Table of Contents (13) Chapters Close

Preface 1. Understanding Spark 2. Resilient Distributed Datasets FREE CHAPTER 3. DataFrames 4. Prepare Data for Modeling 5. Introducing MLlib 6. Introducing the ML Package 7. GraphFrames 8. TensorFrames 9. Polyglot Persistence with Blaze 10. Structured Streaming 11. Packaging Spark Applications Index

Parameter hyper-tuning


Rarely, our first model would be the best we can do. By simply looking at our metrics and accepting the model because it passed our pre-conceived performance thresholds is hardly a scientific method for finding the best model.

A concept of parameter hyper-tuning is to find the best parameters of the model: for example, the maximum number of iterations needed to properly estimate the logistic regression model or maximum depth of a decision tree.

In this section, we will explore two concepts that allow us to find the best parameters for our models: grid search and train-validation splitting.

Grid search

Grid search is an exhaustive algorithm that loops through the list of defined parameter values, estimates separate models, and chooses the best one given some evaluation metric.

A note of caution should be stated here: if you define too many parameters you want to optimize over, or too many values of these parameters, it might take a lot of time to select the best model as...

lock icon The rest of the chapter is locked
Register for a free Packt account to unlock a world of extra content!
A free Packt account unlocks extra newsletters, articles, discounted offers, and much more. Start advancing your knowledge today.
Unlock this book and the full library FREE for 7 days
Get unlimited access to 7000+ expert-authored eBooks and videos courses covering every tech area you can think of
Renews at $19.99/month. Cancel anytime
Banner background image